Thyroid And Parathyroid Agents Flashcards

1
Q

What are the two hormones that the thyroid produces?

A

Thyroid hormone and calcitonin -

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2
Q

What are the two thyroid hormones that are produced using iodine found in the diet and what do they do?

A

Tetraiodothyronine or levothyroxine (t4)- 4 iodine atoms
And
Triiodothyronine or liothyronine (T3)- 3 iodine atoms
Thyroid cells remove the iodine from the blood, concentrates it and prepares it for attachment to tyrosine, an amino acid. Which in turn, makes our thyroid hormone.
Must ingest enough iodine in order to make these hormones.

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3
Q

What are the functions of thyroid hormones?

A

-Regulate the rate of metabolism
-Affect heat production and body temperature
-Affect oxygen consumption, cardiac output, and blood volume
-Affect enzyme system activity
-Affect metabolism of carbohydrates, fats and proteins
-Regulate growth and development

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4
Q

What controls the thyroid gland to release hormones?

A

The pituitary gland. - when TH is low, it will release:
- thyroid stimulating hormone
-T3 and T4 will then circulate in the blood stream.
-pituitary gland will sense the t3 and t4 which will then decrease tsp production so then the thyroid will not secreted more.

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5
Q

What regulates the pituitary gland?

A

Hypothalamus - tsh releasing hormone- trh
Thyroid stimulating hormone releasing hormone.

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6
Q

How many types of thyroid dysfunction are there and what are they?

A

Hypothyroidism: Underactivity - is more common
Hyperthyroidism: Overactivity

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7
Q

What are the causes of hypothyroidism (Underactivity)?

A

-Absence of thyroid gland
-Lack of sufficient iodine in the diet to produce these hormones needed level of thyroid hormone - have iodine salt here in America
-Lack of sufficient functioning thyroid tissue due to tumor or autoimmune disorders- most common dz- hashimotos
-Lack of TRH related to a tumor or disorder of the hypothalamus
-Lack of TSH due to pituitary dz

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8
Q

How would you define hyperthyroidism?

A

Excessive amounts of thyroid hormones are produced and released into circulation-

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9
Q

What is the most common cause of hyperthyroidism?

A

Graves dz.

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10
Q

What are the signs and symptoms of hypothyroidism?

A

Vague and there are many.
Some include obesity and fatigue

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11
Q

What are the Signs and symptoms of hyperthyroidism?

A

-Increased body temperature, tachycardia, thin skin, palpitations, hypertension, flushing, intolerance to heat, amenorrhea, weight loss, and goiter.- enlargement of the thyroid. Over stimulated by tsh.

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12
Q

Use of thyroid and parathyroid agents across the lifespan: CHILDREN

A

Hypothyroidism: Hyperthyroidism: Hypercalcemia: seen in pts with cancer
- Levothyroxine- -Methimazole. -Rare
- higher doses. -Don’t use: -Bisphosphonates
- monitor thyroid labs. Propylthiouracil. -Monitor calcium levels
- monitor growth and development Radioactive agents

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13
Q

Use of thyroid and parathyroid agents across the lifespan: ADULTS

A

-Hypothyroidism: Lifelong, monitor thyroid labs, Pregnancy and lactation: levothyroxine
-Hyperthyroidism: Side effects worse with methimazole- can cause bone marrow suppression greater go and cns effects, sodium iodide can effect fertility, pregnancy: Propylthiouracil- less drug passes through placenta, do not use in lactation.
-Hypercalcemia: Osteoporosis, Monitor calcium levels, Calcium and vitamin D supplements, Pregnancy: DO not use bisphosphonates during lactation.

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14
Q

Use of thyroid and parathyroid agents across the lifespan: OLDER ADULTS

A

Hypothyroidism: Screen regularly, start low go slow, Levothyroxine, Monitor response: Thyroid levels, cardiac effects
Hyperthyroidism: sodium iodide- good option, monitor for hypothyroidism- within a year of antithyroid medication.
Hypercalcemia: Dietary deficiencies: calcium and vitamin D supplements, osteoporosis: BISPHOSPHONATES-help move calcium back into bone, renal impairment, monitor calcium levels.

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15
Q

What are the names of the thyroid hormones?

A

-Levothyroxine
-liothyronine
-Liotrix
-Thyroid Desiccated- dried animal thyroid tissue- pigs important to know cultural religion of patients.

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16
Q

Actions of thyroid hormones

A

Increases cellular metabolism - which increases o2 consumption, respirations, hr, increases rate of body tissues which increases rate of fat protein carbohydrate metabolism effecting growth and maturation. Increases cellular metabolism in all areas of our body.

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17
Q

Thyroid Hormones indications

A

-Hypothyroidism- organisms still working
-Myxedema coma- have a severe hypothyroidism- decreased mental status and other symptoms of slowing of functioning- medical emergency, high mortality rate. - organisms not working
-Pituitary TSH suppression in treatment of euthyroid goiters- goiter even tho th are normal, if given Th then the pituitary would slow release of it.
-Management of thyroid cancer;
-Thyrotoxicosis in conjunction with other therapy - hyperthyroidism where there are signs and symptoms- why would we give TH?- if we give external TH it would have more circulating then maybe PG will stop the release.- monitored very closely

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18
Q

Why would an acute MI be a contraindication to giving this drug?

A

Because it can cause cardiac effects, - if they have hyporthyroidism and it is complicating MI then we might give supplements. This is called MI complicated by hypothyroidism.

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19
Q

Why would thyroidtoxicosis be a contraindication to give thyroid hormone to?

A

hyperthyroidism where there are signs and symptoms- why would we give TH?- if we give external TH it would have more circulating then maybe PG will stop the release.- monitored very closely

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20
Q

why would we want to use caution when giving thyroid hormones to someone with hypo adrenal conditions?

A

Addison dz, body can’t handle drug effects

21
Q

Adverse effects for patients taking thyroid hormones

A

There will be no adverse effects when they are taking correct dose
-euthyroid
Sometimes in the beginning you see skin reactions including hair loss in kids,
Symptoms if hyperthyroidism if given too much
Cardiac stimulation
CNS effects- anxiety, insomnia, and headache

22
Q

Why would anticoagulants be a drug-drug interaction when taking thyroid hormones?

A

It can increase bleeding - check levels and may need to decrease anticoagulant

23
Q

Why is digoxin a drug-drug interaction when taking thyroid hormones?

A

Decrease digoxin level

24
Q

Why would Theophylline be a drug to drug interaction when taking thyroid hormones?

A

Decrease clearance of Theophylline when pt has hypothyroidism so may be on lower does- when they move to new thyroid state may need increase in dose

25
Q

How would you want to administer thyroid hormones?

A

-Single daily dose before breakfast each day
-administer with a full glass of water
-do not administer other drugs at the same time

26
Q

Implementation other than administration of drug

A

Monitor response carefully when beginning therapy especially cardiac response -can take 6 weeks to see therapeutic levels.
Arrange for periodic blood tests- thyroid function

27
Q

What are the two categories of antithyroid agents?

A

THIOMIDES: Propylthiouracil (PTU), Methimazole -
IODINE SOLUTIONS: Srong iodine solution, potassium iodide, Sodium iodide I131 and I123

28
Q

What are antithyroid agents used for?

A

For hyperthyroidism

29
Q

THIOMIDES action

A

Prevent formation of thyroid hormones within the thyroid cells

30
Q

Iodine solutions action and indications

A

Action
Sodium iodide I131 and I123 - enters thyroid cells and destroys them by giving off radiation.

Strong iodine solution and potassium iodide- high doses saturate the thyroid cells preventing hormone formation.

Indications:
Sodium iodide I131 and I123
Low dose: Diagnosis/avaluate thyroid function
High dose: Hyperthyroidism, radiation emergencies- women who cannot become pregnant and older adults who can’t have surgery.

Strong iodine solution and potassium iodide- more commonly used.
Hyperthyroidism, radiation emergencies, suppression of thyroid gland before surgery, acute thyrotoxicosis.

31
Q

Contraindication for antithyroid agents

A

Known allergy

32
Q

What is a caution when giving antithyroid agents?

A

PTU- liver impairment

33
Q

Adverse effects for Antithyroid agents

A

-AII: hypothyroidism
-Methimazole: Bone marrow depression
-PTU: severe liver toxicity
-Iodine solutions: Iodism

34
Q

Drug drug interactions for antithyroid agents

A

-Oral anticoagulants-
Theophylline
Beta-blockers
Digoxin

Monitor when pt moves from hyper to euthyroid state because metabolism affects levels of these drugs. Can also effect antithyroid drug levels

35
Q

Implementation for antithyroid agents

A

-Administer Propylthiouracil three times a day around the clock
-Give iodine solution through a straw; tablets can be crushed - can stain teeth. If unable to swallow can crush and give through straw so doesn’t stain teeth.

  • assess pts receiving iodine solution for any sign of iodism- sore mouth, gums sore, mouth burns, headache, metallic taste.
  • risk for injury rt bone marrow suppression
    Decreased cardiac output- bc we are slowing things down.
    Changes in metabolism- nutrition
36
Q

What are the types of parathyroid dysfunction?

A

-HYPOPARATHYROIDISM
The absence of parathormone
Most likely to occur with the accidental removal of the parathyroid glands during thyroid surgery.
HYPERPARATHYROIDISM
The excessive production of parathormone
Can occur as a result of parathyroid tumor or certain genetic disorders

37
Q

How is calcium controlled in the body?

A

Equilibrium is maintained by an interplay of calcium absorption from the intestines movement of calcium in and out of bones and the kidneys ability to reclaim and excrete calcium with urine.
If serum calcium levels are full the Parathyroid glands will release parathormone into blood, this signals the osteoclasts to release calcium from bone surfaces.
Parathormone also signals the kidneys to reclaim more calcium. Stimulates the active form of vitamin D.
Parathormone- parathyroid glands, calcitonin- cells in thyroid gland. and calcitriol- active form of vitamin D. Synthesized in kidneys under control of PTH.
Special cells in the thyroid gland release calcitonin into the blood, signals osteoclasts to slow down the removal of calcium from the bone and this will lower levels of blood calcium. When we remove it from bone it goes into the blood stream. Can turn off calcitonin which Allows osteoclasts to break down brown and released into blood stream. Day to day calcium regulation.

38
Q

What are the antihypocalcemic agents and what are their actions?

A

-Teriparatide
-Parathyroid hormone
-Calcitrol (Vitamin D)

Actions: Stimulation of osteoclasts to release calcium from the bone
Increased intestinal absorption of calcium
Increased calcium reabsorption from the kidneys - can also retain calcium by releasing phosphorus
Stimulation of cells in the kidney to produce calcitriol
Teriparatide: Stimulates new bone formation.

*Note: calcium and phosphorus have an inverse relationship.

39
Q

What are the indications for taking antihypocalcemic agents?

A

Management of hypocalcemia in pts undergoing chronic renal dialysis -
Treatment of hypoparathyroidism
Teriparatide: treatment of osteoporosis

40
Q

What are the contraindications and cautions when taking antihypocalcemic agents?

A

Contraindications: Allergy, Vitamin D toxicity
Caution: History of renal stones.- made of calcium, could increase renal stones.

41
Q

Adverse effects of Antihypocalcemic agents

A

GI effects
CNS effects

42
Q

Drug-drug interactions for antihypocalcemic agents

A

-Magnesium containing antacids - can lead to increase intestinal absorption magnesium
-Digoxin toxicity with Hypercalcemia - digtoxicity

43
Q

Implementation when taking antihypocalcemic agents

A

-monitor serum calcium levels
-provide supportive measures
-Arrange for a nutritional consultation
-provide thorough pt teaching

44
Q

What are the antihypercalcemic agents and what are the indications?

A

Biphosphonates: These drugs act on the serum levels of calcium and not directly on the pear thyroid gland or PTH.
Inhibits bone resorption-
Indications: osteoporosis, pagets dz
Hypercalcemia in cancer
-Etidronate
-Ibandronate
-Pamidronate
-Risedronate
-Alendronate
Calcitonins: Hormones secreted by the thyroid gland to balance the effects of PTH
Inhibits bone resorption
Indications: Osteoporosis, pagets dz, emergency treatment of Hypercalcemia.
-Calcium salmon

45
Q

What are absolute and relative contraindications of antihypercalcemic agents?

A

ABSOLUTE:
Biphosphonates: Allergy, hypocalcemia
Calcitonins: allergy to fish
RELATIVE:
Biphosphonates: renal dysfunction, GI dz, prolonged use.
Calcitonins: Pregnancy, renal dysfunction, pernicious anemia.

46
Q

Adverse effects for antihypercalcemic agents

A

Biphosphonates: GI: abd pain, nausea and diarrhea/constipation
Esophageal erosion
Bone pain with pagets dz

Calcitonins: Flushing of the face and hands, skin rash, nausea and vomiting, urinary frequency, local inflammation at injection site- injectable

47
Q

Drug- drug interactions with antihypercalcemic agents

A

Biphosphonates: other meds affect absorption- give at least 30 mins apart, aspirin
Calcitonins: None

48
Q

Implementation for antihypercalcemic agents

A

Bisphosphonates: administer on an empty stomach with a full
glass of water 30-60 minutes before other food or medication.
Remain upright for 30 minutes after administration.- hard on stomach and esophagus- can cause erosion is refluxed up.
• Ensure adequate hydration- excretion through kidneys
• Arrange for concomitant vitamin D, calcium supplements, and
HRT
• Calcitonins: Rotate injection sites and monitor for inflammation
• Monitor serum calcium regularly
• Arrange for periodic blood tests of renal function
• Provide comfort measures- analgesics for bone pain.